.App {
  text-align: center;
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
}

.app_head {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 64px;
  background-color: #dbeff3;
  display: none;
}

.app_side {
  position: absolute;
  top: 64px;
  left: 0;
  bottom: 0;
  width: 320px;
  background-color: #707472;
  display: none;
}

.app_main {
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
  background-color: #fff;
}